BACKGROUND: Blood is often irradiated before transfusion for severely immunocompromised patients to prevent a potentially fatal complication of transfusion-associated GVHD. STUDY DESIGN AND METHODS: This study evaluates the effects of X-ray radiation on platelet and lymphocyte rheology because the ability of these blood cells to deform is vital to their flow throughout the microvascular system. Micropipette aspiration experiments were conducted on platelets and lymphocytes exposed to X-ray radiation doses of 0 (control), 25, and 50 Gy. RESULTS: A significant increase in the Young modulus of elasticity was observed between control platelets and irradiated platelets at 25 Gy (p = 0.02) and 50 Gy (p = 0.03). Percent cell activation increased significantly in 25 Gy-irradiated platelets (p = 0.008). In addition, lymphocytes irradiated at 25 Gy have a higher viscosity than controls (p < 0.02). A significantly larger number of activated cells is found in the 50 Gy-irradiated lymphocyte population (p < 0.04). CONCLUSION: The changes in the deformability and activation of irradiated platelets and lymphocytes may reduce local blood flow and lead to intermittent blockage, which may cause a change of blood flow in microvasculatures.
BACKGROUND: Blood is often irradiated before transfusion for severely immunocompromised patients to prevent a potentially fatal complication of transfusion-associated GVHD. STUDY DESIGN AND METHODS: This study evaluates the effects of X-ray radiation on platelet and lymphocyte rheology because the ability of these blood cells to deform is vital to their flow throughout the microvascular system. Micropipette aspiration experiments were conducted on platelets and lymphocytes exposed to X-ray radiation doses of 0 (control), 25, and 50 Gy. RESULTS: A significant increase in the Young modulus of elasticity was observed between control platelets and irradiated platelets at 25 Gy (p = 0.02) and 50 Gy (p = 0.03). Percent cell activation increased significantly in 25 Gy-irradiated platelets (p = 0.008). In addition, lymphocytes irradiated at 25 Gy have a higher viscosity than controls (p < 0.02). A significantly larger number of activated cells is found in the 50 Gy-irradiated lymphocyte population (p < 0.04). CONCLUSION: The changes in the deformability and activation of irradiated platelets and lymphocytes may reduce local blood flow and lead to intermittent blockage, which may cause a change of blood flow in microvasculatures.